(a) Technical Field
The present disclosure relates to a blower motor of a heating, ventilating and air conditioning (HVAC) system for a vehicle, more particularly, it relates to a blower motor of an HVAC system capable of improving heat dissipation efficiency of elements attached to a substrate.
(b) Description of the Related Art
In general, the HVAC system of a vehicle performs a function of introducing air of a high temperature or a low temperature to the inside of the vehicle to control indoor temperature or humidity, and is carried out by rotation of a blower fan, the blower fan being driven by a blower motor.
A power supply is connected to the blower motor connected to the blower fan such that voltage applied to the blower motor is adjusted according to a voltage control signal input so that the amount of blowing air is adjusted.
However, when a lock error (or a stall) of the motor is generated during driving of the blower motor, overcurrent is formed and thus heat is generated, thereby causing damage to the blower motor and a driving circuit.
In order to prevent damage to the blower motor during the lock error, a field effect transistor (FET) device having a heat sink may be attached to the blower motor to control the blower motor and to protect the blower motor during the lock error of the motor.
Specifically, if the blower motor is in a stalled state and thus generates heat due to overcurrent and reaches a predetermined temperature or higher, the FET device performs a function of stopping driving of the blower motor through cutoff of voltage and short-circuit of a temperature fuse using a dual safety device.